Possible future uses of the wireless network include sending live video transmissions from a fire or other emergency scene to a command center, and tracking vehicles with Automatic Vehicle Location systems, he said. According to city documents, workers will also be able to read water meters remotely, and monitor and control traffic signals in an attempt to ease congestion and divert traffic away from hazards.

The network was primarily designed for data communications but is also capable of converting phone calls to voice-over-IP transmissions, Chelson said. It is based on the Universal Mobile Telecommunications System (UMTS) standard, a newer technology being used by some carriers that will support broadband data rates of up to 1.2Mbit/sec. for mobile users, he said. At that data rate, emergency vehicles speeding along at 70 miles per hour should be able to keep a constant connection even as signals are handed off from one cell antenna to another.

Northrop Grumman has already worked on public safety wireless projects in Ohio and the U.K., but this is the company's first UMTS deployment. Chelson noted that New York would have needed many thousands of Wi-Fi antennas if it had used that technology. By comparison, the city will require about 400 UMTS cellular antennas, most of which will be erected atop buildings.

IPWireless Inc. is providing the radio technology for the project, and Cisco Systems Inc. is supplying the network switches. Northrop Grumman won the contract for the network after New York tested its system and one from Motorola Corp., according to city documents.

One common concern of cellular users is whether a network can be reached from inside large buildings, where metal can impede the signals. Chelson said Northrop Grumman's contract doesn't require support for radio communications inside buildings. The new network does perform "quite well in-building, but it all depends on the construction of the building," he said, adding that radio signal repeaters could be added inside buildings if needed.